The Sharpening /Detail tab that is in ACR as well as the Detail function in Lr has a feature that shows you where the sharpening detail is taking place.

To see this, make sure that your image is at 100% or higher, then press Alt and do a left mouse click on the slider point.

It does this for all of the Detail sliders, but the most effective is the Masking slider that gives you a heads-up on finding the edges that are being sharpened. At 100%, when you first Alt+click on the slider for Masking, the screen will be completely white. As you slide to the right, it will start to turn black. SLide until you see the B&W outline and you are seeing the edges that sharpening is being restricted to.

Edge sharpening is the way to go!

The preview that gets generater is the B&W preview that is shown for a lot of other of the ALt+left click slider in all versions of Photoshop.